By Lily Chen, Taiwanese student, Phd Candidate, Griffith School of Engineering
Change of climate includes changes in the hydrological cycle, atmosphere circulation and ocean circulation. Changes in the hydrological cycle have a great impact on human life such as the availability of fresh water and capability of the existing flood mitigation. As rainfall is one of the key components of the hydrological cycle, too much rainfall can cause floods and too less rainfall would cause droughts. In 2006 and 2007, Australia was facing a serious drought problem, but in late 2008 it started having too much rainfall and caused some regional floods. The most recent floods which were caused by summer rainfall in 2010/2011 brought great damage and financial losses in South East Queensland.
I am a PhD candidate at Griffith School of Engineering, currently working on the influence of climate change and urbanisation on urban floods. According to the observed weather data, I found that the mean surface temperature has increased in the past century in most of the Australian regions. The increase of surface temperature leads to an increase of evaporation and the moisture in the air, which could possibly increase the rate of rainfall. This may have an impact on flood occurrences in Australia.
In the Griffith school of Engineering, we have people working on the impacts of climate change on different fields, such as rainfall, evaporation, storm surge, reservoir storage, flood risk and road pavement. In our weekly seminars, we exchange our research experience and I developed different ideas about climate change from different aspects of our collaborations. Some people argue that climate change is not because of global warming. It changes seasonally, they say, that is why we have summers and winters. It is always interesting to see how people think differently.
Due to population growth and urbanisation, more impervious areas have been created. The local surface temperature is higher than it used to be. The demand of water supply is higher than before, because more water is needed for more people. The damage from floods is worse because we have buildt more properties. Whether the climate is changing or not, we need to be prepared for the worst case scenario. It may be costly, but it will be worthwhile when extreme events occur. For example, we can upgrade the stormwater drainage systems or levees of our cities and towns. It is much the same idea as people buying insurance; we do not want to have a car accident, but when it happens, we are covered.